Elevated tank



Sept. 10, 1963 .JENG c. sHANG ELEVATED TANK 2 sheets-sheet 1 Filed Sept.25, 1961 PIGI 24 1HHHHHH FIG. 2

INVENTO Jeng C Shang MVM.) /W l Ams.

Sept. 10, 1963 JENG c. sHANG ELEVATED TANK Filed sept. 25. 1961 2Sheets-Sheet 2 FIG 5 INVENTOR.v Jeng C Shar'lg' United States Patent OFiled Sept. 25, 1961, Ser. No. 140,441 10 Claims. (Cl. 220-18) Thepresent invention relates to elevated tanks and, in particular, toelevated tanks having relatively large capacity storage vessels.

It is an object of the present invention to provide a new and improvedelevated tank.

It is another .object of the present invention to provide an elevatedtank having a relatively small amount of external supportingconstruction.

It is a further object of the present invention to provide in anelevated tank a new and improved storage vessel.

It is a further object of the present invention to provide in a-nelevated tank a lstorage vessel constructed so as to have less deadwater weight.

It is another object of the present invention to provide in an elevatedtank a storage vessel which is designed to embody relatively thin bottomplates.

It is a further object of the present invention to provide an elevatedtank wherein a central riser construction is designed to supportsubstantial portions of the bottom of a storage vessel.

It is yet another object of the present invention to provide in anelevated tank a new .and improved storage vessel having a bottom that isdesigned to provide less dead water weight, yet ris supported by acentral riser construction.

The above and other objects are realized in accordance with the presentinvention by providing a new and improved elevated tank embodying Iastorage vessel supported above the ground level. The storage vessel isot the generally toroidal type and, to this end, embodies a bottomconstruction having segments of a torus. The bottom portion has multiplesections which are suitably connected together to produce a minimum ofdead water space, yet at the same time can be fabricated from relativelythin p-lates .or the like. A transition .riser construction is supportedon the top of a riser structure to coact with the bottom sections of thestorage vessel and support the weight of the vessel and its storedliquid.

The invention, both as to its organization and method ott operation,taken with further objects and .advantages thereof, will best beunderstood by reference to the Ifollowing description taken inconnection with the accompanying drawings, in which:

FIG. 1 is a fragmentary front elevational view of one embodiment of anelevated tank embodying the features of the present invention;

FIG. 2 is a fragmentary sectional view of the tankl of FIG. l;

FIG. 3 is an enlarged sectional view of a portion of the tank of FIG. 2;

FIG. 4 is an enlarged view of a portion of the tank of FIG. 2;

FIG. 5 is a .fragmentary sectional view of a second embodiment of thetank of FIG. l; and

FIG. 6 is 1an enlarged view of a portion of the tank of FIG; 5.

.Referring now to the drawings, one embodiment of the elevated tankembodying the principles of the invention is illustrated in FIGS. 1through 4 and is generally identilied by reference numeral 10. Anotherembodiment of an elevated tank embodying the priciples .of the presentinvention is illustrated in FIGS. 5 and 6 and is generally identifiedIby rete-rence numeral 110. Both of the elevated all designed to containapproximately 500,000 gallons to 2 million lgallons of liquid. Each ofthe elevated tanks 10 and 110 may be characterized as embodying agenerally toroidal storage -vessel vsupported by a center riseroonstruction .and an outer peripheral column structure.

yConsidering lirst the elevated .tank 10 illustrated in FIGS. l through4, the elevated tank 10 is. supported on a suitable foundation 12embedded in the ground 14 so as to .extend vertically upward above theground 14. The tank 10 includes a generally' toroidaal sto-rage vessel16 supported at a ldesired elevation `above the ground 14 by both acentral .riser structure 17 and a plurality of periphtanks 10 and 110are of relatively large capacity and are Y erally arranged columns 18.The riser structure 1'7 briefly comprises a cylindrical *body portion Z0which supports yat its upper end a riser transition construction 22. Theriser transition construction 22 coacts with the central bottom portionof the toroidal storage vessel 16 and is designed so` that additionalsupporting columns llocated inward-1y of the peripheral columns 18 arenot required. The supporting columns 1S are horizontally spaced apartand coact with the side of the storage vessel 16 at vpoints adjiacent toits vertical tangency.

Referring now to the constructional details of the torcivdal storagevessel 16, it functions to house liquid, for

example water, at a desired elevation and, to this end, the vessel loVis entirely hollow. As shown in FIGS. 1 land 2, the storage vessel 16is generally toroidal in construction and comprises a generallyspherical roof portion 24 (shown only in FIG. l) and la generallyto-roidal portion 26 that comprises both the side and part of thebotto-m of the vessel 16 (see FIG. 2). In addition to the toroidalside-bottom portion 26, the bottom of the vesselp comprises anintermediate toroidal section 2S, the outer edge of which isappropriately connected, by welding or the like, to the inner edge ofthe botto-zn section 26, thereby dening an annular junction 30. Theinner edge of the intermediate toroidal section 2S is suitably secured,by welding or the like, to the outer edge of lan inner, lgenorallycurved section 32, thereby providing an annular junctio-n The innercurved section 32 in its preferred form has a generally spherical shapeand is suitably apertured at 36 to accommodate .the upper end of aydowncomer 38 disposed within the riser transition construction 22 andthe riser structure 17. As is well known, the

liquid stored in the vessel 16 is conducted between the vessel 16 andtheground 14 via the downcomer 38.

The elevated storage vessel 16 is solely supported by the horizontallyspaced columns 18, the riser structure 17 and its associated riser`transition construction 22. As best shown in FIG. 2, the side of thevessel-.16 is supported by the column 1S, while the bottom of the vessel16 is supporte-d :solely by .the riser Itransition construction 22 andriser structure .17. Although not clearly illustrated, the riser body 20ot the riser structure 17 is fabricated from many generally cylindricalsections (not shown) that are. vertically aligned and suitably securedtogether by welding `or the like. As clearly illustrated, the risertransition construction 22 is solely supported on the upper end of theriser structure 17 and, to this end, the lower annular end 22a of .theriser transition construction 22 is suitably secured by welding or thelikek to .the upper annular end 20a of the .riser body 20. In order 'tocounteract the inwardly directed `forces applied by theriser transitionconstruction 22 .-to the riser structure 17, Ian annular compressionring 40 is. ixedly secured, by welding or the like, to the junction ofthe above referred edges -20aand 22a. By this arrangement, the inwardly.directed details of the rise transition construction 22, it comprises alower part 42 having a hollow, generally inverted, conical shape. Theconical part 42 is inclined relative to the vertical by an angle alphawhich, in one form of an elevated tank `designed to have a capacity2,000,000 gallons, is approximately 17. The upper annular end 42a of theconical part 42 isfsuitably secured, by welding or the like, to anannular junction 46 comprising (l) the lower annular ends 40a of aninner support cylinder 48 which directly supports the adjacent edgesofthe inner spherical section 32 and the intermediate toroidal section28 and (2) the lower annular edge of an outer generally conicalstructure 50 which supports the junction 30 of the intermediate toroidalsection 20 and the outerv-toroidal section 26.

More specifically, the inner support cylinder 43, as the name implies,in substantially cylindrical in shape and has a diameter equal to thediameter of the inner spherical toroidal section 2S. As a res-ult, theentire inner section 32 and a portion ofthe intermediate section 28 areiixedly supported by the cylinder 48.

Returning to a description of the generally conical structure 50, it islocated outwardly of the inner support cylinder 48 and interconnects thejunction 46 (of the lower end 48a of the cylinder 43 and the upper end42a of the conical part 42) with the junction 30 ofthe outer section 26and intermediate section 28. More particularly, the generally conicalsection 50 includes a lower part 52 having a hollow and inverted conicalshape. lts lower annular end 52a has a diameter slightly larger thanthat of the inner support cylinder l0 and is suitably secured, bywelding or the like, to both the upper end 42a of part 42 and the lowerend 44a of the cylinder 44. The generally conical part 52 is inclinedrelative to the vertical by an angle beta which, in a form of anelevated tank designed to have a capacity of 2,000,000 gallons, isapproximately 38. As shown in FIG. 2, the upper annular end 52b of theconical part 52 is suitably secured, by welding or the like, to thelower annular end 54a of -an intermediate part S4 having a hollow,ygenerally inverted, conical shape. In contrast to the lower conicalpart 52, the Iintermediate conical part 54 is inclined relative to thevertical by an angle gamma which, in a form of an elevated tank designedto have a capacity of 2,000,000 gallons, is approximately 45.

It will be appreciated by reference to HG2 that the upper annular endS41: of the generally conical part 54 is located beneath and inwardly ofthe junction 30 of the outer and intermediate toroidal sections 26. and2S. In order to provide lmaximum support for this junction 30, there isprovided a soacalled 45 knuckle 56 which, as clearly shown in FIG. 2,has a generally curved shape, preferably of elliptical form. The lowerannular end 56a of the knuckle 56 is, of course, xedly attached, byvwelding or the like, to the upper annular end 5411 of the conical part54, while the upper end Sb o-f the knuckle S6 is suitably secured to thejunction 30.

The connection between the knuckle 56 [and the junction 30 is clearlyshown in FIG. 3. As illustrated, the upper annular end `56h of theknuckle Sti is ixedly secured to the inner end 26a of the outer toroidalsection 26 and also also to the outer edge 2811 of the intermediatetoroidal section 28. As 4is well known, in the design of storagevessels, it is :desirable that the horizontal components of the load,i.e. the weight of the stored liquid, attributed to adjacent sections ofthe bottom of the vessel be subsantially equal. However, because of thesize of the outer -toroidal section 26 relative to the intermediateltoroidal section 28, there exists a horizontal torce. componentdirected outwardly, which component in the absence of additionalsupporting structure tends to `dislocate the adjacent toroidal sections26 and Accordingly, in order to offset the outwardly :directedhorizontal force components, a tension ring 50 (see FIGS. 2 and 3) isxedly secured, by welding or the like, to the junction 30. By thisarrangement, the horizontal force components are effectively neutralizedand an extremely stable bottom construction is provided.

lt will be appreciated that by designing the storage vessel loAdifferently than described above, the horizontal force components,attributed to the load carried by the toroidal section Z6 and thetoroidal section 2S, respectively, could be equal to one another. Whenthese force components are equal, there is no tendency for one toroidalsection to dislocate an `adjacent toroidal section. However, if it weredesired to equate these horizontal components, it would be necessary toincrease the radius or curvature of the toroidal section 2S andconsequently decrease 'the radius of curvature of the inner section 32.The resulting effect would be that the inner section 32 would cover toosmall an 'area and, thereby, would be over-designed in the sense that itwould not be stressed to its maximum allowable stress. Specically, itthe inner section 32 had 1a quarter inch plate thickness, which is theminimum #allowable thickness for plate used in elevated tanks, theintermediate section 23 would not be stressed anywhere near itslallowable stress. Accordingly, the design `oi the inner section 32would be highly ineiicient since a mulch thinner platte than the minimumallowable plate thickness could be used. Hence, the cost of the elevatedtank would be unnecessarily increased.

On the other hand, if it were desired to equalize the abovehorizontal'orce components at the junction 30, the radius of curvatureof the intermediate section 2S would have to be increased to such anextent that a much thicker plate would be required.

In accordance with the present invention, the outer section 26, theintermediate section 28, and the inner section 32 (the bottom of thestorage Vessel i6) are designed to develop their maximum allowablestresses, thereby providing a highly etlicient bottom for the storagevessel le requiring a minimum of cost. At the same time, the bottom of:the storage vessel i6 is designed to have a minimum of dead waterspacewhich is defined by the concave portions of the bottom lyingbeneath the upper end of the downcorner 38. This design is made possibleto some extent by the use of the inner support cylinder i8 acting onlthe junction 34 of the inner and intermediate sections 32 and` 2h and,also, the tension ring 53 acting on the junction 30 of the outer andintermediate sections 26 land 28.

Considering now in greater detail yan analysis ot the load forcecomponents, attention is invited to FIGS. 3 and 4. ln FlG. 4 wherein thejunction 34 is illustrated, the forces `attributed to the weight of thewater carried by the inner section 32 and the intermediate section 20(and acting tangentially iat the junction 34) arc represented as forcevectors, identiiied as P1 and P2, respectively. lt will be noted thatthe force vector P1 is directed `inwardly while the force vector P2 isdirected outwardly. Because `of the disposition and magnitude of theseforce vectors, it is apparent that the resultant horizontal component isdirected outwardly. However, at the junction 34, the inner supportcylinder 4S effectively resists and overcomes this youtwardly directedhorizontal component thereby preventing an imbalance of forces at thejunction 34 and, furthermore, absorbs the vertical component of theforces.

With respect to the junction 30 illustrated in FIG. 3, it will beappreciated that the forces attributed to the weight of water carried bythe intermediate section 28 and the outer section 26 (and actingtangentially at the junction 30) are represented as force vectors,identified as P3 and P4. As shown, the fonce vector P3 is directedinwardly, while the torce vector P4 is directed outwardly. Because oftheir relative disposition and magnitude, the resultant horizontalcomponent is directed outwardly. At the junction 30, the tension ring 58effectively resists and offsets this outwardly directed horizontalcompo-nent, thereby preventing lan imbalance of forces Iat the junction30. Of course, the vertical compone-nt of the forces is absorbed by theknuckle 56;.

Although the riser rtransition construction 2Z`h1as been described ascomprising a conical part 42 disposed below an inner support cylinder 43(about which is disposed a pair of conical parts 52 and 54 and a knuckle56), 4it should yalso be understood that, depending upon the design andcapacity of a tank of the present invention, the riser transitionconstruction can be diiierently constructed. For example, Aif the innerspherical section has a larger diameter than that illustrated, a pair ofconical parts could be disposed beneath the support cylinder and asingle conical part, as well as a 45 knuckle, could be disposed aboutthe cylinder, which of course would have a larger diameter than thatillustrated. Alternatively, instead of using an inner support cylinder43, la generally conical inner support could be used. In either case,the inner support member would function to overcome any imbalance ofhorizontal force attributed to the weight of the load carried by theinner and intermediate sections at the junction 34. Hence, it will beappreciated that the riser transition construction can be modified inaccordance with the demands of the particular installation, butirrespective' of its modilied orm, the transition construction willnonetheless support the junctions 3u and 34 of the botto-rn of thestorage vessel 16.

Considering now the embodiment of the elevated tank 110 illus-mated inFIGS. 5 `and 6,. the elevated tank 11) embodies the same constructionalcomponents as the tank 1i), with the exceptitm that inwardly directedcolumns and associated ties Iare substituted for the tension ring 58. lnthe interest of avoiding unnecessary duplication of description, theconstructional ldetails of the riser, riser transition construction, andthe elevated storage vessel will not be repeated. Instead, components inthe elevated tank 110, which are identical to components in elevatedtank 10, will be identified by reference numeraisincreased by 100.

As previously suggested, instead of -using a tension ring 58 at thejunction 3o, a plurality of inclined columns 112 (only two of which areshown) extend between the junction 130 and the columns 118.Specifically, as shown in FIG. 6, the inner end 126e of the outertoroidal section 126,'the outer end 128i; of the intermediatey toroidalSection 128, the upper end 156b of the knuckle 15,6, and the upper end112:1 of the inclined column 112 are suitably secured together,bywelding or the like. Hence, even though the resultant horizontal forcecomponent is directed outwardly, the inclined supporting column 112,having compression characteristics, produces an inwardly directed forcecomponent that effectively resists and overcomes the resultanthorizontal component. As shown in FlG. 5, additional supportingstructure may alternatively be used and, in this connection, ties 114are disposed between the junction` 113 of the inclined column 112 andthe vertical column 11S and the junction 115 of the riser structure 117and theriser transition structure 122. Additional columns 116 may beprovided so as to extend between an intermediate point on each of theties 114 and supporting structure located beneath the ties. Accordingly,irrespective of whether a tension ring or an inclined columnconstruction is employed, the bottom of the storage vessel 16 isoptimumly designed to provide an extremely eiicient construction whichis economical to build and whichhas extremely little dead water space.

While several embodiments described herein are at present consideredtobe preferred, it is understood that various modica-tions andimprovements may be made therein, and it is intended to cover in theappended claims all such modiiications and improvements as fall withinthe true spirit and scope of the invention.

What is desired to be claimed and secured by Letters Patent of theUnited States is:

l. An elevated tank comprising a vessel for storing liquids at anelevated level; said vessel having a bottom including an outer generallytoroidal section, an intermediate generally toroidal section, andaninner generally curved section; supporting means coacting with thevessel at points outwardly of the lowest portion of the outer sectionfor supporting the vessel and its stored liquid; riser transitionconstruction including means supporting the juncture of the outer andintermediate sections and the'juncture of thel intermediate and innersections; and a riser structurefcoacting with the riser transitionconstruction for supporting the vessel and its stored liquid. .-2. Anelevated tank comprising a vessel for storing liquids at an elevatedlevel; said vessel having a bottom including an outer generally toroidalsection, an intermediate generally toroidal section, and an innergenerally curved section; supporting means coacting with the vessel atpoints outwardly of the lowest portion of the outer section forsupporting the vessel and its stored liquid;

riser transition construction including means supporting,

the juncture of the outer and intermediate sections and the juncture ofthe intermediate and inner sections; means connected to the juncture ofthe outer and intermediate sections for counteracting an imbalance ofthe horizontal components of the load forces of the outer andintermediate sections acting at the juncture; and a riser structurecoacting with the riser vtransition construction for supportingthe'vessel and its stored liquid.

3. An elevated tank comprising a vessel for storing liquids at anelevated level; said vessel having a bottom including an outer generallytoroidal section, an intermediate generally toroidal section, and aninner generally curved section; supporting means coacting with thevessel at points outwardly of the lowest portion of the outer sectionfor supporting the vessel and its stored liquid; riser transitionconstruction including means supporting the juncture of the outer andintermediate sections and the juncture of the intermediate and innersections; a riser structure coacting with the riser transitionconstruction -for supporting the vessel and its stored liquid, anda'downcomer arrangement located within said riser transitionconstruction and said riser structurekfor conducting liquid between thevessel and the ground.

4. An elevated tank comprising a vessel for storing liquids at anelevated level; -said vessel having la bottom including Van outergenerally to-roidal section, and intermediate generally tor-oidalsection, and :an inner generally curved section, said outer,intermediate, and inner sections being suitably secured together inliquid-tight relationship; means Icoasting with the vessel to supportthe weight of the vessel and its sto-red liquid; riser transitionconstruction including means supporting the juncture of the outer andintermediate sections and the juncture of the intermediate and innersections; and a riser structure icoacting with the riser transitionconstruction for supporting the vessel and its stored liquid.

5. An elevated tank comprising a vessel nor storing liquids at anelevated level; said vessel having a bottom including. an outergenerally toroid-al section, an inten mediate generally to-roidalsection suit-ably secured along its outer edge to the inner edge of saidouter section, and an inner generally curved section secured along itsouter edge Kto the inner edge of said intermediate section; meansengaging the outer toroid'al section at joints outwardly of its lowestportion for supporting the vessel and its stored liquid; risertransition construction including means supporting the joined edges ofsaid outer section 'and intermediate section `and the joined edges ofsaid intermediate section and said inner section; means connected to theintersection of the outer and intermediate sections for counteracting animbalance of horizont-al components of the load forces of the Iouter andintermediate sections acting at the intersection, 'and a riser structuresupponting the riser transition construction for supporting ythe storagevessel 'and its stored liquid. y

6. An lelevated tank comprising a vessel for storing liquids at anelevated level; said vessel having a bottom including yan outergenerally toroidal section, said outer,

intermediate, and inner sections being suitably secured.

together in liquid-tight relationship; means coacting with the vessel tosup-port fthe Weight of the vessel Iand its stored liquid; risertransition construction including van upwardly and outwardly ared.bottom portion, means supported by the bottom portion for supportingthe juncture or" the inner and intermediate sections, and meanssupported by the bottom portion for supporting the juncture of theintermediate and outer sections; and a riser structure coacting with thelbottom portion of the riser transition construction for supporting thevessel and its stored liquid.

7. An elevated tank comprising a vessel for storing liquids at anelevated level; said vessel having a bottom including an outer generallytorcidal section, said outer, intermediate, and inner sections beingsuitably secured together in liquid-tight relationship, means enactingwith the vessel to support the Weight of the vessel and its storedliquid; riser transition construction including an upwardly andoutwardly ared bottom portion, mean supported by the bottom portion forsupporting the juncture of .the inner and intermediate sections, andmeans supported by the bottom portion 'for `supporting the juncture ofthe intermediate and outer sections; means con- S nected to the junctureof the outerfiand intermediate sections for counteracting an imbalanceat the juncture of the horizontal components of the load forces of theouter land intermediate sections acting Iat the juncture; and a riserstructure coacting with the ybottom portion of the riser transitionconstruction for supporting 'the vessel and its stored liquid.

8. The .tank of claim 6 wherein said means supporting lthe juncture ofthe intermediate and outer sections includes :an outwardly flared`section and a curved section supported by said iiared section andterminating in a substantially vertically oriented section that coactswith the last mentioned juncture.l

9. The tank of cil-aim 2 wherein said counteracting means comprisestension ring means for opposing the resultant outvvandly directed:horizontal component of the load forces provided lby the intermediateand outer sections.

l0. The tank of `claim 2 wherein said counteracting means comprises aplurality of inclined column means interconnecting the juncture of theintermediate and router sections and the vessel supporting means.

References Cited in the le of this patent UNITED ySTATES PATENTS2,335,184 Houseman Nov. 22, 1943 `2,349,096 iackson May 16, 19442,768,432 Hines Oct. 30, 1956 2,961,118 Miller Nov. 22, 1960

1. AN ELEVATED TANK COMPRISING A VESSEL FOR STORING LIQUIDS AT AN ELEVATED LEVEL; SAID VESSEL HAVING A BOTTOM INCLUDING AN OUTER GENERALLY TOROIDAL SECTION, AN INTERMEDIATE GENERALLY TOROIDAL SECTION, AND AN INNER GENERALLY CURVED SECTION; SUPPORTING MEANS COACTING WITH THE VESSEL AT POINTS OUTWARDLY OF THE LOWEST PORTION OF THE OUTER SECTION FOR SUPPORTING THE VESSEL AND ITS STORED LIQUID; RISER TRANSITION CONSTRUCTION INCLUDING MEANS SUPPORTING THE JUNCTURE OF THE OUTER AND INTERMEDIATE SECTIONS AND THE JUNCTURE OF THE INTERMEDIATE AND INNER SECTIONS; AND 